Add support for spoofed zip Central Dir names at Entry level

Author: jvazquez-r7

lib/rex/zip/archive.rb

@@ -38,9 +38,11 @@ def add_r(dir)
   #
   # If fdata is set, the file is populated with that data
   # from the calling method. If fdata is nil, then the
-  # fs is checked for the file.
+  # fs is checked for the file. If central_dir_name is set
+  # it will be used to spoof the name at the Central Directory
+  # at packing time.
   #
-  def add_file(fname, fdata=nil, xtra=nil, comment=nil)
+  def add_file(fname, fdata=nil, xtra=nil, comment=nil, central_dir_name=nil)
     if (not fdata)
       begin
         st = File.stat(fname)
@@ -62,7 +64,7 @@ def add_file(fname, fdata=nil, xtra=nil, comment=nil)
       end
     end
 
-    @entries << Entry.new(fname, fdata, @compmeth, ts, attrs, xtra, comment)
+    @entries << Entry.new(fname, fdata, @compmeth, ts, attrs, xtra, comment, central_dir_name)
   end
 
 

lib/rex/zip/blocks.rb

@@ -116,7 +116,11 @@ def initialize(entry, offset)
   end
 
   def pack
-    path = @entry.relative_path
+    if @entry.central_dir_name.blank?
+      path = @entry.relative_path
+    else
+      path = @entry.central_dir_path
+    end
 
     ret = [ SIGNATURE, ZIP_VERSION ].pack('Vv')
     ret << [ ZIP_VERSION ].pack('v')

lib/rex/zip/entry.rb

@@ -8,11 +8,12 @@ module Zip
 #
 class Entry
 
-  attr_accessor :name, :flags, :info, :xtra, :comment, :attrs
+  attr_accessor :name, :flags, :info, :xtra, :comment, :attrs, :central_dir_name
   attr_reader :data
 
-  def initialize(fname, data, compmeth, timestamp=nil, attrs=nil, xtra=nil, comment=nil)
+  def initialize(fname, data, compmeth, timestamp=nil, attrs=nil, xtra=nil, comment=nil, central_dir_name=nil)
     @name = fname.unpack("C*").pack("C*")
+    @central_dir_name = (central_dir_name ? central_dir_name.unpack("C*").pack("C*") : nil)
     @data = data.unpack("C*").pack("C*")
     @xtra = xtra
     @xtra ||= ''
@@ -71,10 +72,12 @@ def compress
 
 
   def relative_path
-    if (@name[0,1] == '/')
-      return @name[1,@name.length]
-    end
-    @name
+    get_relative_path(@name)
+  end
+
+  def central_dir_path
+    return nil if @central_dir_name.blank?
+    get_relative_path(@central_dir_name)
   end
 
 
@@ -104,6 +107,15 @@ def inspect
     "#<#{self.class} name:#{name}, data:#{@data.length} bytes>"
   end
 
+  private
+
+  def get_relative_path(path)
+    if (path[0,1] == '/')
+      return path[1, path.length]
+    end
+    path
+  end
+
 end
 
 end